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Comment by xutopia | Hacker News Reader

Was this intravenous vitamin C at much higher dosage than we usually see from oral supplementation?

From the Methods section of the paper [1].

> For vitamin C experiments, mice undergoing standard feeding or at the last day of the first FMD cycle started to be treated with vitamin C (4 g/kg in saline) via intraperitoneal injection twice a day, every day until the end of the experiment. At least 6–8 h have elapsed between the two administrations in each day.

EDIT: 4 g/kg twice a day is about 400 grams (0.88 pounds) of Vitamin C per day for a 50 kg (110 pound) person. 1 gram per day is a good rule of thumb for the upper limit of oral supplementation.

[1] https://www.nature.com/articles/s41467-020-16243-3.pdf#page=...

Thank you for posting the link to Nature. From the paper, the FMD decreases the ferritin available to tumor cells which makes them more vulnerable to the hydrogen peroxide produced by the metabolism of vitamin C. Do I have that right?

From what I've read there's a cap on how much VitC you can absorb orally, IV VitC can give you much much more (think order of magnitude or more).

You can handle pretty large doses of oral Liposomal Vitamin C.

Really? How many pounds of it do you think you could eat in a day?

> Figure3 shows plasma levels following a 36g dose of liposomal vitamin C, for both subjects. This resulted in peak plasma levels, in the region of 400mML21. A 95% interfractile range (34–114), which contains 95% of the distribution with a mean of 74 corresponds to a calculated standard deviation of 17.4. We note that, under these conditions, an outlier measurement of 400mML21 would correspond to a deviation of 10.3 s with a theoretical p-value of 1.6610213 (i.e. p,0.0000000000001). With this high dose, both subjects exceeded their bowel tolerance, leading to diarrhoea. This intolerance presumably arose from the high intake of phospholipid, without food buffering, in fasting individuals. However, our observations using hourly doses suggest that daily intakes of this magnitude are tolerable without bowel effects, as long as the dose is spread throughout the day. https://www.tandfonline.com/doi/abs/10.1080/1359084080230542...

Thanks for the info. I wasn't going to bother answering his stupid question, but the answer is "a lot".

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